1. Field of the invention
The invention concerns a gas-fired heating device particularly suitable for burning the horns of livestock animals.
2. Description of the prior art
The horns of horned livestock animals such as cattle and sheep are periodically burned to limit their growth and prevent accidents. The devices used for this comprise a handle, a heat source and a nozzle heated by the heat source. The nozzle has a cup-shaped surface which is substantially a surface of revolution about the axis of the handle. To burn a horn the nozzle of the device is fitted over the end of the horn and the device is rotated on itself by manipulating the handle.
Some devices of this kind are electrically operated and function at the AC line voltage (220 V, for example), electrical safety being procured either by a ground connection or by double insulation. In the former case it is necessary to provide at a reasonable distance from the place of use an electrical power socket outlet with a proper ground connection, which is not always available in farms. Also, as the electrical power cord of these devices is relatively short it is generally necessary to use an extension cable and this must incorporate a ground conductor. Even if all these conditions can be met, there is still the risk of electrical connections being made in a humid environment or even in water. Finally, movements of the animals may pull out or break the wires.
The same constraints and the same hazards apply in the case of double-insulated devices, except for those resulting from the necessity for a ground connection.
For these reasons the European standards organizations are considering a ban on the marketing of devices of this kind.
There are also electrical devices operating from a low-voltage (24 V) supply and therefore requiring a voltage-reducing transformer. Once again, an electrical power supply is needed. The electrical safety problems are solved provided that the transformer is connected directly to the AC line supply, with no intermediate junction points in a humid environment. However, the presence of the transformer significantly increases the cost of the product, all the more so in that the standards organizations require the transformer to be splashproof.
Finally, there are gas-fired devices which connect to a gas cylinder via a pressure regulator and a hose. A device of this kind can be used at places where there is no fixed power supply. However, these devices do require a gas cylinder and a pressure regulator which, if acquired specifically for this application, increase the cost of the equipment. The weight of the cylinder also tends to limit its mobility. The device produces a flame which projects to the exterior of the device and therefore constitutes a fire hazard.
An object of the invention is to eliminate the disadvantages of the known devices and to provide an inexpensive, self-contained device that is totally mobile and eliminates virtually all risk of accidents.
Another object of the invention is to provide a gas-fired heating device offering relatively high power and a relatively high operating temperature combined with compact overall dimensions and therefore good handiness while preventing any excessive heating of the handle.